Learn how to read microphone sound visualizations. Understand what speech, noise, and silence look like in audio visualizations.
The microphone test offers two visualization modes to help you understand your audio input. Each shows different aspects of the sound your microphone captures.
Frequency bars
Frequency bars display the volume level at different frequency ranges of your audio input. Each bar represents a frequency band, from low frequencies (bass) on the left to high frequencies (treble) on the right.
Tall bars: Loud sounds at that frequency
Short bars: Quiet sounds or silence at that frequency
Peak markers: Show the maximum level reached at each frequency — they stay at the highest point until you reset
This view is best for quickly checking that your microphone is picking up sound and seeing which frequencies are most prominent in your audio.
Look at the overall shape of the bars to understand your audio:
Speech: Activity concentrated in the low-to-mid range (roughly 80Hz–4kHz), with bars rising and falling as you speak. Bars should drop to near zero when you stop talking
Background noise: Persistent low bars that stay active even during silence — fans and air conditioning typically show as steady low-frequency bars
Electrical hum: A single persistent bar at 50Hz or 60Hz (depending on your power frequency)
Silence: All bars near zero or completely flat. Some low-level activity is normal — microphones have a noise floor
Spectrogram
A spectrogram is a visual representation of the frequency content of sound over time. It reveals patterns that frequency bars cannot show.
Horizontal axis: Time — the display scrolls from right to left as new audio arrives
Vertical axis: Frequency — low frequencies at the bottom, high frequencies at the top
Color intensity: Volume — brighter colors mean louder sounds, muted areas mean silence
The spectrogram is especially useful for seeing how your voice changes over time and whether background noise is constant or intermittent.
Different sounds create distinctive visual patterns:
Speech: Horizontal bands (called formants) that shift as you form different vowels and consonants, with dark gaps during pauses between words
Fan / air conditioning: A constant bright band at the bottom of the display that never fades
Broadband noise (hiss): A uniform glow across all frequencies — visible as an even color fill
Silence: Dark / no color across the display. If you see bright areas when you are not speaking, that is background noise
If you see significant noise, consider reducing it. See our noise reduction guide for tips.
Tips for better readings
Consistent distance: Keep the same distance from your microphone for comparable results
Reduce background noise: Close windows, turn off fans, and minimize ambient sound for cleaner visualizations
Use both modes: Frequency bars are great for a quick check; spectrogram reveals patterns over time
Use with recording: Record yourself and compare what you see in the visualization with what you hear on playback